[libc-commits] [libc] 3b0c457 - [libc] add shared divdf3 builtin (#205675)

[via libc-commits]

Author: hulxv
Date: 2026-07-01T15:02:00Z
New Revision: 3b0c4575ec629192c54b2504a32dc99692e3973f

URL: https://github.com/llvm/llvm-project/commit/3b0c4575ec629192c54b2504a32dc99692e3973f
DIFF: https://github.com/llvm/llvm-project/commit/3b0c4575ec629192c54b2504a32dc99692e3973f.diff

LOG: [libc] add shared divdf3 builtin (#205675)

Re-exposes LLVM-libc's `__divdf3` as `shared::divdf3` for reuse by
compiler-rt's builtins.

Stacked change - merge these first:
- #200094
- #205669
- #205670
- #205671
- #205672
- #205673
- #205674

Part of #197824

Added: 
    libc/shared/builtins/divdf3.h
    libc/src/__support/builtins/divdf3.h

Modified: 
    libc/shared/builtins.h
    libc/src/__support/builtins/CMakeLists.txt
    libc/test/shared/CMakeLists.txt
    libc/test/shared/shared_builtins_test.cpp

Removed: 
    


################################################################################
diff  --git a/libc/shared/builtins.h b/libc/shared/builtins.h
index 2540be78519d7..94ff3fb32ee69 100644
--- a/libc/shared/builtins.h
+++ b/libc/shared/builtins.h
@@ -19,6 +19,7 @@
 
 #include "builtins/adddf3.h"
 #include "builtins/addtf3.h"
+#include "builtins/divdf3.h"
 #include "builtins/divtf3.h"
 #include "builtins/muldf3.h"
 #include "builtins/multf3.h"

diff  --git a/libc/shared/builtins/divdf3.h b/libc/shared/builtins/divdf3.h
new file mode 100644
index 0000000000000..4cabc847b7a02
--- /dev/null
+++ b/libc/shared/builtins/divdf3.h
@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This header exposes LLVM-libc's __divdf3 implementation as shared::divdf3 so
+/// that it can be reused by compiler-rt's builtins.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SHARED_BUILTINS_DIVDF3_H
+#define LLVM_LIBC_SHARED_BUILTINS_DIVDF3_H
+
+#include "shared/libc_common.h"
+#include "src/__support/builtins/divdf3.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace shared {
+
+using builtins::divdf3;
+
+} // namespace shared
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SHARED_BUILTINS_DIVDF3_H

diff  --git a/libc/src/__support/builtins/CMakeLists.txt b/libc/src/__support/builtins/CMakeLists.txt
index 179337c4d6cf0..69b9de039d465 100644
--- a/libc/src/__support/builtins/CMakeLists.txt
+++ b/libc/src/__support/builtins/CMakeLists.txt
@@ -64,3 +64,12 @@ add_header_library(
     libc.src.__support.FPUtil.generic.mul
     libc.src.__support.macros.config
 )
+
+add_header_library(
+  divdf3
+  HDRS
+    divdf3.h
+  DEPENDS
+    libc.src.__support.FPUtil.generic.div
+    libc.src.__support.macros.config
+)

diff  --git a/libc/src/__support/builtins/divdf3.h b/libc/src/__support/builtins/divdf3.h
new file mode 100644
index 0000000000000..b9af2252be389
--- /dev/null
+++ b/libc/src/__support/builtins/divdf3.h
@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This header exposes LLVM-libc's __divdf3 implementation as builtins::divdf3
+/// so that it can be reused by compiler-rt's builtins.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_BUILTINS_DIVDF3_H
+#define LLVM_LIBC_SRC___SUPPORT_BUILTINS_DIVDF3_H
+
+#include "src/__support/FPUtil/generic/div.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace builtins {
+
+// Division at double precision; mirrors compiler-rt's __divdf3.
+LIBC_INLINE double divdf3(double x, double y) {
+  return fputil::generic::div<double>(x, y);
+}
+
+} // namespace builtins
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_BUILTINS_DIVDF3_H

diff  --git a/libc/test/shared/CMakeLists.txt b/libc/test/shared/CMakeLists.txt
index 3d4255f8539c7..7986d5f00ee5b 100644
--- a/libc/test/shared/CMakeLists.txt
+++ b/libc/test/shared/CMakeLists.txt
@@ -829,6 +829,7 @@ add_fp_unittest(
   DEPENDS
     libc.src.__support.builtins.adddf3
     libc.src.__support.builtins.addtf3
+    libc.src.__support.builtins.divdf3
     libc.src.__support.builtins.divtf3
     libc.src.__support.builtins.muldf3
     libc.src.__support.builtins.multf3

diff  --git a/libc/test/shared/shared_builtins_test.cpp b/libc/test/shared/shared_builtins_test.cpp
index be89aea684e8e..e7e06452da8bc 100644
--- a/libc/test/shared/shared_builtins_test.cpp
+++ b/libc/test/shared/shared_builtins_test.cpp
@@ -16,6 +16,7 @@ TEST(LlvmLibcSharedBuiltinsTest, AllFloat) {
 
 TEST(LlvmLibcSharedBuiltinsTest, AllDouble) {
   EXPECT_FP_EQ(3.0, LIBC_NAMESPACE::shared::adddf3(1.0, 2.0));
+  EXPECT_FP_EQ(3.0, LIBC_NAMESPACE::shared::divdf3(6.0, 2.0));
   EXPECT_FP_EQ(6.0, LIBC_NAMESPACE::shared::muldf3(2.0, 3.0));
   EXPECT_FP_EQ(2.0, LIBC_NAMESPACE::shared::subdf3(5.0, 3.0));
 }